Swallowing problems (dysphagia) associated with age-related diseases are a growing healthcare concern, with epidemiological studies suggesting that dysphagia will affect over 20% of adults 50 years of age and older. The modified barium swallow study (MBSS) is the most commonly used method for assessment of oropharyngeal dysphagia used by speech-language pathology and radiology teams. Specificity of age-related changes observed on MBSS has not been adequately detailed in large numbers of healthy, non-dysphagic adults to differentiate impairment from healthy age-related changes in swallowing function. Although several studies have explored age related changes using temporal, pressure, and kinematic measures, participant samples have been inadequately powered to capture true variation in impairment or study methods included limited trials with small, functionally irrelevant bolus volumes of only one consistency. This gap in knowledge drives the purpose of this proposed prospective study using innovative and well-tested methods designed to measure swallowing function in healthy, non-dysphagic adults across the adult aging continuum and opens opportunities for future interventional research. The immediate project goal will uncover the normal variation in oropharyngeal swallowing behavior that occurs with normal aging and incorporates a quantitative approach for measurement of physiologic observations obtained from MBS examinations. This study, designed to identify and quantify these changes, is highly significant. Further, the identification of swallowing changes that go beyond those anticipated with normal aging may lead to identification of MBS biomarkers that represent the early onset of disease. Lastly, behavioral therapies known to target these abnormal physiologic changes seen on MBS could be tested for their early neuroprotective effect on the swallowing mechanism in patients with progressive neurological disease. The findings from this proposal will lead to submission of a CDA-2 application, in which the applicant will propose to study the effects of empirically based interventions that directly targets physiologic impairment through systematic exercise regimens in patients with progressive neurological disease (e.g., Parkinson's disease).]